tests: adjust whitespace in chainlint expectations

The "check-chainlint" target runs automatically when running tests and performs self-checks to verify that the chainlinter itself produces the expected output. Originally, the chainlinter was implemented via sed, but the infrastructure has been rewritten in fb41727b7e (t: retire unused chainlint.sed, 2022-09-01) to use a Perl script instead. The rewrite caused some slight whitespace changes in the output that are ultimately not of much importance. In order to be able to assert that the actual chainlinter errors match our expectations we thus have to ignore whitespace characters when diffing them. As the `-w` flag is not in POSIX we try to use `git diff -w --no-index` before we fall back to `diff -w -u`. To accomodate for cases where the host system has no Git installation we use the locally-compiled version of Git. This can result in problems though when the Git project's repository is using extensions that the locally-compiled version of Git doesn't understand. It will refuse to run and thus cause the checks to fail. Instead of improving the detection logic, fix our ".expect" files so that we do not need any post-processing at all anymore. This allows us to drop the `-w` flag when diffing so that we can always use diff(1) now. Note that we keep some of the post-processing of `chainlint.pl` output intact to strip leading line numbers generated by the script. Having these would cause a rippling effect whenever we add a new test that sorts into the middle of existing tests and would require us to renumerate all subsequent lines, which seems rather pointless. Signed-off-by: Patrick Steinhardt <ps@pks.im> Reviewed-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>